As an infectious-disease specialist, I often see patients who complain of a headache, nasal congestion and short-term fatigue. There is no fever or cough, and it appears the problem is sinusitis, which requires no further testing or treatment. But when I say, "Let's wait and watch," many of my patients seem disappointed. In some cases, it seems they are satisfied only if I prescribe an antibiotic or order a blood test or X-ray.

I understand where they are coming from: I often feel similarly let down when I take my daughter to the pediatrician for an earache and leave without a prescription for an antibiotic.

When we go to the doctor, most of us want something done, even if the benefits are questionable or marginal. Both parties are at fault: Many patients demand tests, and often doctors encourage them. How much excess care is being carried out is debatable, but some studies indicate that nearly 30 percent of U.S. health-care expenditures are unnecessary. That would be $700 billion of waste each year.

Choosing Wisely, a new campaign supported by several professional medical societies and consumer groups, is encouraging doctors and patients to kick this habit — to curb the overuse of tests and procedures, including the prescription of antibiotics and imaging studies for sinusitis within the first seven days of symptoms.

In April, the ABIM Foundation, which is affiliated with the American Board of Internal Medicine, published a list of 45 overused tests and procedures, including routine electrocardiograms during a physical and imaging studies for back pain.

As a doctor and, at times, a patient, I can appreciate the need for Choosing Wisely. I often come upon situations where the doctor-patient encounter feels like a push-and-pull dance, with both partners leaning toward overtreatment. As patients, we push for more tests, genuinely fearing a debilitating or fatal illness such as pneumonia, cancer or heart disease. Some of us do not understand that more testing can be harmful due to radiation, medication side effects or a spurious lab finding that begins a cascade of unnecessary and invasive diagnostic tests.

As a doctor, I pull for more tests because I'm genuinely concerned about missing a diagnosis or apprehensive about malpractice suits, or because I lack time to carefully talk to or examine patients but want to satisfy their demands.

All of this is exacerbated when there isn't a strong doctor-patient relationship. When working in the emergency room once, I had 15 minutes to make a judgment about whether a patient's headache was due to a migraine, sinus infection, pain-medication-seeking behavior or a life-threatening bleed in the brain. With no previous relationship with the patient and no certainty that he would return to the emergency room if his symptoms worsened, the best option was to order a CT scan of the head "just in case." As one doctor told me: "No one will ever sue you for ordering an extra CT scan."

Sadly, concern for patients and malpractice anxiety are not the only reasons for excessive testing. Some doctors who overtest are motivated by financial self-interest, especially if they own the lab doing the test, which is fairly common. I know an internist who orders a chest X-ray and blood count for anyone with a cough and a cardiologist who routinely has patients with chest pain give consent for a cardiac catherization — all before talking with or examining them. These extra tests tend to lead to more procedures, which means more money for the doctor.

Choosing Wisely is a first bold attempt for doctors to self-regulate this sort of behavior. Yet however admirable, I don't think a "just say no" approach to overtesting and overtreatment will work. A better system would approach the problem three ways: defined measurement, peer-to-peer reporting and payment alignment.

Let me explain. I believe I am guilty of overtesting my patients and overprescribing antibiotics to them, yet I do not know my own data: how many particular tests or expensive antibiotics I have prescribed compared with my peers. We need individualized physician data on who is doing the testing, and how much of it. We need to measure because only then will we know if we have improved.

Second, we need to compare our rates of testing and procedures among peers at a local level. This will stimulate conversation on best practices and the use of guidelines. As a doctor in private practice, I never sit with peers and compare my cost and quality data.

Last, we need to establish payment incentives for less testing. Moving toward bundled or global payments — where a fixed amount is paid for a particular diagnosis or a given patient, rather than payment for individual tests — can add real teeth.

To make the campaign successful, patients also need to change their behavior. Patients should be encouraged to ask questions about the risks and benefits of a given test and how the results will affect their health. Moreover, a punitive measure such as higher co-pays and higher deductibles might discourage some patients from demanding excessive testing and procedures.

To be sure, it would take time for these changes to take root. But they can begin with small steps. To get over my tendency to overtest or overtreat my sinusitis patients, for example, I have borrowed a trick from my daughter's pediatrician.

When a patient insists that I take some action but I am on the fence about the value of doing so, I write a prescription for a test or an antibiotic. But then I ask the patient to wait four to five days before filling it. Usually with a viral infection, the patient feels better before that time is up and decides to forgo the test or the antibiotic. Often reassurance, tincture of time and patient choice work well.

Christine K. Cassel, the president of the American Board of Internal Medicine, told me that Choosing Wisely is not about eliminating tests but about deciding whether we need to do a test or treatment. Ultimately, when doctor and patient both agree to forgo a particular test, it is not rationed care; it is rational care.